A known water pump, disclosed in, for example JP2003-314491A, includes a pulley, a shaft portion, an impeller, a body, a bearing, a mechanical seal and a cover. Specifically, the shaft portion rotates integrally with the pulley, the impeller rotates integrally with the shaft portion, the body includes an approximate cylindrical supporting portion into which the shaft penetrates, the bearing is provided between an outer peripheral surface of the supporting portion and an inner peripheral surface of the pulley so as to rotatably support the pulley, the mechanical seal seals a space formed between an outer peripheral surface of the shaft portion and an inner peripheral surface of the supporting portion at one end of the space.
Further, a drain hole is formed on a front wall of the pulley in order to drain vaporized coolant or micro-stillformed coolant, which has leaked through the mechanical seal, to an atmosphere side. The cover, being cylindrical having a bottom, is fixed to a front surface of the pulley so as to cover the front wall of the pulley.
According to such the known water pump, vaporized coolant or micro-stillformed coolant has leaked through the mechanical seal, passed through a drain hole and been drained into the cover, and then the coolant gelates and adheres to an inner peripheral surface of the cover so as to prevent the coolant from being spattered. Further, by use of the cover, it can be prevented that foreign objects come into shaft portion.
However, in such the configurations, because the gelated coolant cannot stay inside the cover, the gelated coolant may flow outside the cover, and further, ethylene glycol, which has been colored and included in the antifreezing fluid mixed into the coolant, may be adhere to the front surface of the pulley, as a result, the mechanical seal may be recognized as being damaged, in addition, level of the outer appearance of the water pump can be decreased.
Thus, a need exists for providing a water pump in which fluid leaked through a seal member can be prevented from flowing out of a cover.